Kennametal 6140616 Spiral Flute Tap 8-32 Cobalt Oxide

Product Description

The KENNAMETAL 6140616 is a spiral flute tap designed for threading 8-32 holes in ferrous materials. It features a 45-degree helix angle that evacuates chips upward out of the hole, making it well-suited for blind-hole tapping where chip packing is a concern. The tap is manufactured from cobalt high-speed steel for increased heat and wear resistance compared to standard M2 HSS. An oxide coating provides additional lubricity and mild corrosion resistance. With a modified bottoming chamfer, this tap can thread closer to the bottom of a blind hole than a plug or taper chamfer style. Overall length is 2.13 inches and thread length is 0.38 inches.

This tap is intended for use in steel, stainless steel, and cast iron — workpiece material codes P, M, and K. It is suited for production tapping operations in machine shops, maintenance and repair environments, and toolroom applications where a reliable, consistent thread form in an 8-32 size is required. The H3 thread limit designates a tolerance range appropriate for class 2B and 3B fits in standard unified thread applications. No coolant-through capability is present, so conventional flood coolant or cutting oil applied externally is the standard approach.

Key Features

• 45-degree right-hand spiral flute geometry for upward chip evacuation in blind holes
• Modified bottoming chamfer for threading close to hole bottom
• Cobalt HSS construction for improved wear resistance in hard or abrasive ferrous materials
• Oxide coating for added lubricity and surface protection
• H3 thread limit for consistent class 2B and 3B thread fits
• Right-hand thread direction, compatible with standard tapping attachments and CNC turrets

Compatibility

Designed for tapping 8-32 unified national coarse threads in steel, stainless steel, and cast iron workpieces. Compatible with standard machine tapping chucks, floating tap holders, and rigid tapping setups that accept the 0.168-inch shank diameter.

Installation Notes

This tap is installed by a machinist or toolroom technician in a drill press, CNC machining center, or hand tapping setup. Always ensure the drilled hole is at the correct tap drill diameter for an 8-32 thread before tapping. Apply an appropriate cutting fluid or tapping oil for the workpiece material — sulfurized oil is commonly used for steel and stainless steel. Secure the workpiece and confirm spindle alignment before engaging the tap to avoid tap breakage or cross-threading.